1. JEOPARDY
Functions
Linear Models
Exponential Models
Quadratic Models
Miscellaneous 1 1 1 1 1 2 2 2 2 2 3 3 3 3 3 4 4 4 4 4

2. 1
Functions
For the relation below, state the domain, range, and whether it is a function.
ANSWER

3. 1
Functions
ANSWER
Domain: {-2, -1, 0, 4}
Range: {0, 2, 4, 5}
Function? Yes, because for all ordered pairs (x,y), each value of x is paired with exactly one value of y.
Jeopardy

4. 2
Functions
For the relation below, state the domain, range, and whether it is a function.
ANSWER

5. 2 Domain: all real numbers Range: {y: y ≤ -10 or y ≥ 10}
Functions
ANSWER
Domain: all real numbers
Range: {y: y ≤ -10 or y ≥ 10}
Function? No, because it fails the vertical-line test for a function.
Jeopardy

6. 3
Functions
For a set of data, the correlation coefficient r is -0.9 and the line of best fit is y = mx + b. Which of the following is a true statement?
m > 0
m < 0
m can be any real number
This is a weak correlation.
ANSWER

7. 3
Functions
ANSWER B
Jeopardy

8. 4 Graph y = g(x) on the domain -5 ≤ x ≤ 5.
Functions
Graph y = g(x) on the domain -5 ≤ x ≤ 5.
Find the range of g if the domain is the set of all real numbers.
Give the x-intercepts of the graph of g.
ANSWER

9. 4
Functions
ANSWER a.
{y: y ≤ }
There are no x-intercepts.
Jeopardy

10. 1
Linear Models
Write an equation for the line that passes through (-6, 8) and (3, -1) in slope-intercept form.
ANSWER

11. 1
Linear Models
ANSWER
y = -1x + 2
Jeopardy

12. The values range from ___ to ___.2
Linear Models
A measure of the strength of a linear relation between two variables is the _______________________.
The values range from ___ to ___.
ANSWER

13. correlation coefficient2
Linear Models
ANSWER
correlation coefficient
-1 ≤ r ≤ 1
Jeopardy

14. 3
Linear Models
________ of r indicates the _______ of the relation between the variables.
_________ indicates the __________ of the relation.
Perfect correlation in a situation where r = ___.
ANSWER

15. 3
Linear Models
ANSWER
SIGN of r indicates the DIRECTION of the relation between the variables.
MAGNITUDE indicates the STRENGTH of the relation.
Perfect correlation in a situation where r = ± 1.
Jeopardy

16. 4
Linear Models
The table below gives the percent of the U.S. population who had completed at least four years of college for selected years.
Find an equation for the line of best fit for these data. Let the independent variable be the number of years after 1900.
Use your model from part a to estimate the percent of the U.S. population in 1994 who completed at least four years of college.
What is the error of your estimate in part b?
ANSWER

17. 4
Linear Models
ANSWER
y = 0.19x – 1.42
Approx. 16.4%
1.3%
Jeopardy

18. 1
Exponential Models
ANSWER

19. 1
Exponential Models
ANSWER f
(0, 1)
As x increases, f(x) approaches 0 and g(x) increases without bound. As x decreases, g(x) approaches 0 and f(x) increases without bound.
Jeopardy

20. 2
Exponential Models
ANSWER

21. a. approx. 36.4% b. about 2.64 billion
Exponential Models
ANSWER
a. approx % b. about billion
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22. 3
Exponential Models
Suppose you purchased a car 20 years ago for $15,200. The value of the car decreased by 6% each year. What is the value of the car today?
ANSWER

23. 3
Exponential Models
ANSWER
$4,409.61
Jeopardy

24. 4 Exponential Models A certain substance has a half life of 24 years.
If a sample of 90 grams is being observed, how much will remain in 50 years?
When will only 5 grams remain?
ANSWER

25. 4
Exponential Models
ANSWER
21.24 grams
100 years
Jeopardy

26. 1 If a<0, a parabola has a ___________ point.
Quadratic Models
If a<0, a parabola has a ___________ point.
If a>0, a parabola has a ___________ point.
ANSWER

27. 1
Quadratic Models
ANSWER
maximum, minimum
Jeopardy

28. 2
Quadratic Models
The table below gives the percent of the U.S. population who had completed at least four years of college for selected years.
Use the points (10, 2.7), (40, 4.6) and (70, 11.9) to find a quadratic model for these data. The independent variable represents the number of years after 1900.
Use the quadratic model to predict the percent of the U.S. population having completed four years of college in the year 2010.
ANSWER

29. 2
Quadratic Models
ANSWER
y = 0.003x² x
30.03%
Jeopardy

30. 3
Quadratic Models
Suppose a ball is hit upward from a height of 1 meters with an initial velocity of 35 meters per second.
Find the relation between height h and time t after the ball is hit.
How high is the ball after 3 seconds?
ANSWER

31. 3
Quadratic Models
ANSWER a.
b meters
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32. 4 Let f(x) = 2x² + x – 15. Find the y-intercept of f(x).
Quadratic Models
Let f(x) = 2x² + x – 15.
Find the y-intercept of f(x).
Find the x-intercepts of f(x).
Tell whether the graph has a maximum or minimum point and find its coordinates.
ANSWER

33. 4 (0, -15) (5/2, 0) and (-3, 0) minimum at (-1/4, -121/8)
Quadratic Models
ANSWER
(0, -15)
(5/2, 0) and (-3, 0)
minimum at (-1/4, -121/8)
Jeopardy

34. 1
Miscellaneous
Order the scatterplots shown below in increasing order of correlation coefficient.
ANSWER

35. 1
Miscellaneous
ANSWER
C, B, D, A
Jeopardy

36. 2
Miscellaneous
Evaluate f(n-2)
if f(x) = 2x2 - 4
ANSWER

37. 2
Miscellaneous
ANSWER
2n2 - 8n + 4
Jeopardy

38. y varies inversely as the cube of x3
Miscellaneous
y varies inversely as the cube of x
Suppose that y=10 when x=5.
Find y when x=10.
ANSWER

39. 3
Miscellaneous
ANSWER
y = 1.25
Jeopardy

40. 4
Miscellaneous
Below are graphed the residuals for both the linear and quadratic models. What do these graphs tell you about the appropriateness of each model?
ANSWER

41. 4
Miscellaneous
ANSWER
The residuals for the linear model are positive at both ends, indicating that a better model can be found. The residuals for the quadratic model fall within a horizontal band centered around zero, so the quadratic model is a good fit.
Jeopardy